Mechanical Engineering - Compressors, Gas Dynamics and Gas Turbines - Discussion

The after-cooler is a heat exchanger intended to reduce the temperature of the hot air discharged from the compressor to approximately 15 to 25°C above that of the ambient air.

Two basic types of after-coolers are (1) air-cooled after-cooler and (2) water-cooled after-cooler.

The air-cooled after-cooler uses the ambient air to cool the hot air discharged from the compressor.

In the water-cooled after-cooler, the hot compressed air is passed through the after-cooler tubes and cooling water is passed in the opposite direction through the after-cooler shell.

The counter-current flow provides an effective method for reducing the temperature of the compressed air by reducing the temperature, most of the suspended water vapour and some oil vapour will condense to the liquid state.

The liquid is then drained away from the system.

D must be the right answer.

Intercooler and aftercooler purpose is same as to cool the air. If the cooling is to be done between the stages the cooler is called intercooler and after last stage, the cooler is aftercooler.

So, the Answer must be to cool the air.

Agree, C is the correct answer.

Aftercooler cools the air at constant pressure, thereby reducing the volume, hence storage/container size can be reduced.

So, the Answer is B.

C is the correct answer. Agree with the given answer.

Anyone, Please clarify this in clear.

The answer should be to reduce the volume of air.

After cooler is a device used in multistage compressor in between compressor and receiver the main purpose of these to cooling down the air before send it to receiver and reduces the volume of air.

So answer is to reduce volume of air.